Inside micrometer



Sept. 4, 1945.

J. F. RO-NDINONE INSIDE MICROMETER Filed Jan. 21, 1943 1 N V EN TOR.JOSEPH J? Roma/NONE.

Patented Sept. 4, 1945 INSIDE MICROMETER Joseph F. Rondinone,Wethersfield, Conm, assign or of one-fourth to Winifred C. Rondinone,

Wether'sfield, Conn.

" f Application January 21, 1943, SerialNo. 473,087

Claims.

This invention relatesuto inside micrometers and has for its object toprovide a micrometer formeasuring inside dimensions accurately andwhichwill be easy to read.

. vA further object of -the invention is to provide an inside micrometeremploying a standard type of micrometer mechanism which is veryconvenienttouse. p

Further objects of the invention will be more clearly understood fromthe following description and from the accompanvingdrawing in which:

Fig. 1 is a plan view-of ,an'inside micrometer embodyingmy invention. a

Fig. 2 is a side view thereof.

Fig. 33 is an enlarged-rear view of a portion of the device showing themounting of the swivel connection.

Fig. 4 is a view-in central vertical section of the portion shown inFig.3. v

Fig. 5 is a plan view-on an enlarged scale with parts shown in sectionon;line,55 of Fig. 2.

As shown in the drawing, my improved inside micrometermay employyastructure similar to inside calipers which may consist of legs 5 and Bthat are pivoted at l and have measuring points 8-8.

My invention provides a micrometer construction which is attached to thesaid legs and consists of a conventional form of a micrometer mechanismhaving the usual graduated barrel 9 and the corresponding sleeve H]which operates the slide bar II in the well known manner that it isoperated in the conventional form of micrometers.

A supporting member I2 is secured to the barrel 9 and swivelly connectedto the leg 6, preferably by means of a screw M. The other leg 5 of thecalipers is swivelly connected to the slide bar II by means of pivots,such as screws I5, which engage a swivel block H5. The end of thespindle II is reduced as at l1, extends through the said block l6 and issecured thereto by means of a screw l8 and a washer l9. A spring isprovided, between the said block is and the shoulder 2| on the spindleH, and exerts a tension which forces the block l6 against the washer Hi.This construction eliminates lost motion in the connection between thebar II and the leg 5 and provides the clearance necessary to permitrotation of the spindle l l in the block Hi.

In the use of my invention, such as in measuring the inside of anopening, the points 88 are inserted in the opening and the sleeve I0 isthen turned until the said points engage the walls of the opening or thepoints to be measured.

Contact between said points-or walls will be easily felt, through theresistance applied to the tuming of the sleeve lll just as the contactis actually made, for the reason that the spring 20 keeps the leg 5always in engagement with the end of the spindle l l and eliminates lostmotion, between said leg and the bar, which would otherwise tend tocause error in measuring for close dimensions.

In the construction shown, the graduations on the barrel 9 and thesleeve l0 are spaced according tor-the movement of the points 8--8 on aline indicated at 22, in thisucase; the ratio between the movement atthe points 8-8 on the line 22 and the movement of the legs on the line5--5 being two to one.. In other words, the points 8-8 will moveone-half an inch while the legs will move only one-quarter of 7 an inchat the line 55. This will permit the use of a relatively short barrel 9and sleeve in which is an advantage in the manufacture of myinvention'as Well as in the use thereof. V

Error between the distances actually moved by the points 8,8 and thoseindicated .by the graduations on the barrel 9 is eliminated and the useof a variably graduated scale is rendered unnecessary by the fact that,in the operation of my improved micrometer, the line 22 and the line 5-5are always in parallel positions regardless of the distances between thepoints 8-8 on line 22 and the pivots on line 5. Further, it is to benoted that the member l2 bridges around the leg 5 and that the pivotedblock l6 moves between the pivot I4 and the barrel 9. Thus, the pivotfor the block I6 retains the micrometer measuring mechanism with itsaxis always on line 5-5 and parallel to the line indicated at 22;thereby insuring accurate measurements by maintaining a constantlyuniform ratio between the distances travelled by the points 88 on line22 and by the pivots on line 5.

While I have shown my invention as applied to a caliper construction,the same may also be applied to various other forms of measuring deviceswithout departing from the scope of my invention as set forth in theappended claims.

I claim:

1. An inside micrometer of the character described comprising a pair ofpivoted leg members and a measuring mechanism carried on said membersintermediate the ends thereof; said measuring mechanism including asupporting member pivotally connected to the side of one of said membersand having a portion extending around the other leg member to the outerside thereof, and standard measuring means carried on said supportingmember; said measuring means including a barrel having graduationsthereon and mounted on the said portion of the supporting member, aSleeve movable over said barrel, and a spindle movable with said sleeveand swivelly and rotatably connected to the said other leg member tothereby permit direct reading of the graduations on said barrel. p 3 42. An inside micrometer of theizharacter de-' scribed comprising a pairof pivotally connected leg members having a measuring mechanism mountedthereon intermediate the ends thereof; said measuring mechanismincluding a supporting member swivelly connected to the side of one ofsaid leg members and having ,a portion extend ing around the other legmember to the outer side thereof relative to the first leg member, andstandard measuring means carried "on thesai'd portion of the supportingmember and including a spindle swivelly and rotatably secured to theother leg member to thereby permitdir'ect reading of g-raduations ofsaid measuring ine'chani-s'ml 3; An inside micrometer comprising acaliper construction including apair'of pivotally connected leg membersand a measuring mechanism; said mechanism including a barrel havinga'sleeve movable thereover, a frame extending from said barrel andswivelly connected to one of said leg members-a block pivoted to theother legineinher, a spin-die movable with said sleeve rotatablyconnected to said-block for securing the said measuring mechanism" tosaid other leg member, anchoring means rotatably securing said spindleto said block, and spring means urging said block into engagement withsaid anchoring means to thereby prevent lost motion between the saidblock and spindle.

,ann inside micrometer of the character fl scribed including a 'c'aliperconstruction tempersing a pairpf pivotally ccnneetdle'g members, asupporting member secured to the'si'deof one of said leg members,ap'ortion 'Of said supporting member extending past the side otthe otherleg member and having a bearing portion positioned exteriorly of saidcaliper construction and adjacent to the other leg member, a measuringbarrel mounted on said bearing portion, a measuring sleeve movable oversaid barrel, a spindle connected to said sleeve and rotatable in saidbearing portion and movable along the axis thereof, and means forsecuring said spindle to the other leg member,- s'aid means including abill bf pivoting members threaded to said leg member and projecting intoan opening therein, a pivoted member supported between said pivotingmembers and having an opening therein, a reduced portion on said spindleprojecting through said opening in the pivoted member, anchoring meanson the end of said spindle and abutting the side of said pivoted member,to retain it in position relative to 'sai'd'spindl'e; and a spring onsaid reduced portion urging said pivoted member against said anchoringmeans to prevent lost motion between the said spindle and-pivoted memberv j 5. 4m inside micrometer comprising a caliper consisting of a pair ofpivotally connected legs and a micrometer measuring meohanismbonnedt edto the saideallp'ertor-im'eratin'g said legs, said measuring mecnamsmincluding a frame 'ekte'nd mg to one sweet said caliper and pivotailyconnected to the leg member at the opposite: side of the eali'per andadapted to receive'the' other leg member for movement between the endsthereof, said frame moulding a measuring. mechanism having-a barrelbearmg standard gr'aduations thereon, said barrel being married by saidframe, a measuring sleeve movable over said barrel, and amasiir-ingspindle operation with said sleeve and extending through said barrel andthirtvtalhr and swivelly connected to the said othet igme'fn be-rwherebvthe said 'sll'le'will move outwardly over said barrel uponthe-opening of said eelipe'r and'mwardlv ever said barrelupon theclosing of said caliper and thereby permit direct "reading or saidgmduatiens. I Jasm n RONDINOHE.

